The neural and endocrine mechanisms of sexual and aggressive behaviors will be investigated in non-human primates by remote methods for electrical stimulation of the CNS. Behavioral measures will be correlated with anatomical sites of stimulation and with manipulation of hormonal status by endocrine organ ablation, exogenous stimulation or pharmacological suppression. Radioimmunoassays of gonadotrophic and steroid hormones will be determined in plasma obtained from both electrically stimulated and hormonally manipulated subjects. Blood samples will be obtained from restrained and unrestrained animals. A remote blood withdrawal system will be used in conjunction with remote stimulation of the brain in freely moving rhesus monkeys. BIBLIOGRAPHIC REFERENCES: Cochran, C.A. and Perachio, A. A. Dihydrotestosterone propinate effects on dominance and sexual behaviors in gonadectomized male and female rhesus monkeys. Hormones and Behavior, 1976, In press. Perachio, A. A., Lide, E., Rice, D. H. and Sikes, J. A remotely controlled device for controlling electrical stimulation of the central nervous system. Biotelemetry, Vol. 3, 1976, In press.